Method of making phonogram-blanks



(No Model.) I

v T. A. EDISON.

METHOD OF MAKING PHONOGRAM BLANKS. 7 N6. 400,649.. PatentedApr. 2. 1.889.

- WITNESSES: IIV'I/EAIYTOI? Arm/M15767 UNITED} STATES PATENT OFFICE.

THOMAS A. EDISON, OF LLEWELLYN PARK, NEW JERSEY.

METHOD OF MAKING PHONOGRAM-BLANKS.

SPECIFICATION forming part of'Letters Patent No. 400,649, dated April 2, 1889.

" Application filed October 11,1888. Serial No. 287,843. (NomodeL) To all whom it may concern:

Be it known that I, THOMAS A. EDISON, of Llewellyn Park, in the county of Essex and State of New Jersey, have invented a certain new and useful Improvement in Methods of Making Phonogram-Blanks, (Case No. 807,) of which the following is a specification.

The object of my invention is to produce, in a simple and expeditious manner, cylindrical phonogram-blanks made of paper or other flexible material covered with a material which can be indented by the recording-point of the phonograph.

In carrying my invention into effect, I first take a sheet of paper or other flexible material of the proper size, and I wrap this upon a tapering core which is provided with a handle. I secure the paper together at its edges, and I then, holding the core by the handle, dip it into a bath of the material to be applied to it while such material is in a softened'condition. Thismaterial is prefer-' ably a wax or a composition of waxes or a suitable metallic soap. After the paper is dipped and becomes coated to a sufficient thickness with the indenting material, it is placed in a lathe, and its surface is turned off into a true cylindrical form, it being at first in the'tapering form of the dipping-core. The phonogram-blank being then removed from the core is ready for use.

My invention is illustrated in the accompanying drawings.

Figure 1 is an elevation of the paper wrapped on the dipping-core; Fig. 2, a section of the sameafter dipping and turning, the core being in elevation; and Fig. 3, a cross-section on the line 3 3 of Fig. 2.

The sheet of paper a is wrapped upon the tapering cylindrical core 1;, which has a handle, c, and its overlapping edges are gummed or otherwise secured together. The paper thus assumes a form like that of the core.

The core is then held by the handle and the paper dipped into the material, as above described, and this material d adheres to the surface of the paper, whereby a hollow cylinder tapering both inside and outside is produced. This is then turned off in a lathe into the shape shown in Fig. 2-that is, so that it has a cylindrical outer surface and a tapering bore, whereby on being removed from the forming-core it can readily be placed upon the cylinder of the phonograph and recorded upon.

In placingthe cylinder in the lathe, I prefer-to leave it on the forming-core, this being provided with depressions at its ends (shown in dotted lines) for holding it in the lathe.

What I claim is The method of making a phonogram-blank, which consists in wrapping a sheet of flexible material upon a tapering cylindrical core, dipping the same into the sound-recording material, which is caused to adhere to its surface, and then turning off the surface of such material into a true cylindrical form, substantially as set forth.

This specification sign ed and witnessed this 29th day of September, 1888.

WILLIAM PELZER, E. O. ROWLAND. 

